/* $Header: /roq/tiff/tif_read.c 1     11/02/99 4:39p Zaphod $ */



/*

 * Copyright (c) 1988-1996 Sam Leffler

 * Copyright (c) 1991-1996 Silicon Graphics, Inc.

 *

 * Permission to use, copy, modify, distribute, and sell this software and 

 * its documentation for any purpose is hereby granted without fee, provided

 * that (i) the above copyright notices and this permission notice appear in

 * all copies of the software and related documentation, and (ii) the names of

 * Sam Leffler and Silicon Graphics may not be used in any advertising or

 * publicity relating to the software without the specific, prior written

 * permission of Sam Leffler and Silicon Graphics.

 * 

 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 

 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  

 * 

 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 

 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 

 * OF THIS SOFTWARE.

 */



/*

 * TIFF Library.

 * Scanline-oriented Read Support

 */

#include "tiffiop.h"

#include <stdio.h>

#include <assert.h>



static	int TIFFFillStrip(TIFF*, tstrip_t);

static	int TIFFFillTile(TIFF*, ttile_t);

static	int TIFFStartStrip(TIFF*, tstrip_t);

static	int TIFFStartTile(TIFF*, ttile_t);

static	int TIFFCheckRead(TIFF*, int);



#define	NOSTRIP	((tstrip_t) -1)			/* undefined state */

#define	NOTILE	((ttile_t) -1)			/* undefined state */



/*

 * Seek to a random row+sample in a file.

 */

static int

TIFFSeek(TIFF* tif, uint32 row, tsample_t sample)

{

	register TIFFDirectory *td = &tif->tif_dir;

	tstrip_t strip;



	if (row >= td->td_imagelength) {	/* out of range */

		TIFFError(tif->tif_name, "%lu: Row out of range, max %lu",

		    (u_long) row, (u_long) td->td_imagelength);

		return (0);

	}

	if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {

		if (sample >= td->td_samplesperpixel) {

			TIFFError(tif->tif_name,

			    "%lu: Sample out of range, max %lu",

			    (u_long) sample, (u_long) td->td_samplesperpixel);

			return (0);

		}

		strip = sample*td->td_stripsperimage + row/td->td_rowsperstrip;

	} else

		strip = row / td->td_rowsperstrip;

	if (strip != tif->tif_curstrip) { 	/* different strip, refill */

		if (!TIFFFillStrip(tif, strip))

			return (0);

	} else if (row < tif->tif_row) {

		/*

		 * Moving backwards within the same strip: backup

		 * to the start and then decode forward (below).

		 *

		 * NB: If you're planning on lots of random access within a

		 * strip, it's better to just read and decode the entire

		 * strip, and then access the decoded data in a random fashion.

		 */

		if (!TIFFStartStrip(tif, strip))

			return (0);

	}

	if (row != tif->tif_row) {

		/*

		 * Seek forward to the desired row.

		 */

		if (!(*tif->tif_seek)(tif, row - tif->tif_row))

			return (0);

		tif->tif_row = row;

	}

	return (1);

}



int

TIFFReadScanline(TIFF* tif, tdata_t buf, uint32 row, tsample_t sample)

{

	int e;



	if (!TIFFCheckRead(tif, 0))

		return (-1);

	if (e = TIFFSeek(tif, row, sample)) {

		/*

		 * Decompress desired row into user buffer.

		 */

		e = (*tif->tif_decoderow)

		    (tif, (tidata_t) buf, tif->tif_scanlinesize, sample);

		tif->tif_row++;

		if (e)

			(*tif->tif_postdecode)(tif, (tidata_t) buf,

			    tif->tif_scanlinesize);

	}

	return (e ? 1 : -1);

}



/*

 * Read a strip of data and decompress the specified

 * amount into the user-supplied buffer.

 */

tsize_t

TIFFReadEncodedStrip(TIFF* tif, tstrip_t strip, tdata_t buf, tsize_t size)

{

	TIFFDirectory *td = &tif->tif_dir;

	uint32 nrows;

	tsize_t stripsize;



	if (!TIFFCheckRead(tif, 0))

		return (-1);

	if (strip >= td->td_nstrips) {

		TIFFError(tif->tif_name, "%ld: Strip out of range, max %ld",

		    (long) strip, (long) td->td_nstrips);

		return (-1);

	}

	/*

	 * Calculate the strip size according to the number of

	 * rows in the strip (check for truncated last strip).

	 */

	if (strip != td->td_nstrips-1 ||

	    (nrows = td->td_imagelength % td->td_rowsperstrip) == 0)

		nrows = td->td_rowsperstrip;

	stripsize = TIFFVStripSize(tif, nrows);

	if (size == (tsize_t) -1)

		size = stripsize;

	else if (size > stripsize)

		size = stripsize;

	if (TIFFFillStrip(tif, strip) && (*tif->tif_decodestrip)(tif,

	    (tidata_t) buf, size, (tsample_t)(strip / td->td_stripsperimage))) {

		(*tif->tif_postdecode)(tif, (tidata_t) buf, size);

		return (size);

	} else

		return ((tsize_t) -1);

}



static tsize_t

TIFFReadRawStrip1(TIFF* tif,

    tstrip_t strip, tdata_t buf, tsize_t size, const char* module)

{

	TIFFDirectory *td = &tif->tif_dir;



	if (!isMapped(tif)) {

		if (!SeekOK(tif, td->td_stripoffset[strip])) {

			TIFFError(module,

			    "%s: Seek error at scanline %lu, strip %lu",

			    tif->tif_name,

			    (u_long) tif->tif_row, (u_long) strip);

			return (-1);

		}

		if (!ReadOK(tif, buf, size)) {

			TIFFError(module, "%s: Read error at scanline %lu",

			    tif->tif_name, (u_long) tif->tif_row);

			return (-1);

		}

	} else {

		if (td->td_stripoffset[strip] + size > tif->tif_size) {

			TIFFError(module,

			    "%s: Seek error at scanline %lu, strip %lu",

			    tif->tif_name,

			    (u_long) tif->tif_row, (u_long) strip);

			return (-1);

		}

		_TIFFmemcpy(buf, tif->tif_base + td->td_stripoffset[strip], size);

	}

	return (size);

}



/*

 * Read a strip of data from the file.

 */

tsize_t

TIFFReadRawStrip(TIFF* tif, tstrip_t strip, tdata_t buf, tsize_t size)

{

	static const char module[] = "TIFFReadRawStrip";

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t bytecount;



	if (!TIFFCheckRead(tif, 0))

		return ((tsize_t) -1);

	if (strip >= td->td_nstrips) {

		TIFFError(tif->tif_name, "%lu: Strip out of range, max %lu",

		    (u_long) strip, (u_long) td->td_nstrips);

		return ((tsize_t) -1);

	}

	bytecount = td->td_stripbytecount[strip];

	if (bytecount <= 0) {

		TIFFError(tif->tif_name,

		    "%lu: Invalid strip byte count, strip %lu",

		    (u_long) bytecount, (u_long) strip);

		return ((tsize_t) -1);

	}

	if (size != (tsize_t)-1 && size < bytecount)

		bytecount = size;

	return (TIFFReadRawStrip1(tif, strip, buf, bytecount, module));

}



/*

 * Read the specified strip and setup for decoding. 

 * The data buffer is expanded, as necessary, to

 * hold the strip's data.

 */

static int

TIFFFillStrip(TIFF* tif, tstrip_t strip)

{

	static const char module[] = "TIFFFillStrip";

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t bytecount;



	bytecount = td->td_stripbytecount[strip];

	if (bytecount <= 0) {

		TIFFError(tif->tif_name,

		    "%lu: Invalid strip byte count, strip %lu",

		    (u_long) bytecount, (u_long) strip);

		return (0);

	}

	if (isMapped(tif) &&

	    (isFillOrder(tif, td->td_fillorder) || (tif->tif_flags & TIFF_NOBITREV))) {

		/*

		 * The image is mapped into memory and we either don't

		 * need to flip bits or the compression routine is going

		 * to handle this operation itself.  In this case, avoid

		 * copying the raw data and instead just reference the

		 * data from the memory mapped file image.  This assumes

		 * that the decompression routines do not modify the

		 * contents of the raw data buffer (if they try to,

		 * the application will get a fault since the file is

		 * mapped read-only).

		 */

		if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)

			_TIFFfree(tif->tif_rawdata);

		tif->tif_flags &= ~TIFF_MYBUFFER;

		if (td->td_stripoffset[strip] + bytecount > tif->tif_size) {

			/*

			 * This error message might seem strange, but it's

			 * what would happen if a read were done instead.

			 */

			TIFFError(module, "%s: Read error on strip %lu",

			    tif->tif_name, (u_long) strip);

			tif->tif_curstrip = NOSTRIP;

			return (0);

		}

		tif->tif_rawdatasize = bytecount;

		tif->tif_rawdata = tif->tif_base + td->td_stripoffset[strip];

	} else {

		/*

		 * Expand raw data buffer, if needed, to

		 * hold data strip coming from file

		 * (perhaps should set upper bound on

		 *  the size of a buffer we'll use?).

		 */

		if (bytecount > tif->tif_rawdatasize) {

			tif->tif_curstrip = NOSTRIP;

			if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {

				TIFFError(module,

				"%s: Data buffer too small to hold strip %lu",

				    tif->tif_name, (u_long) strip);

				return (0);

			}

			if (!TIFFReadBufferSetup(tif, 0,

			    TIFFroundup(bytecount, 1024)))

				return (0);

		}

		if (TIFFReadRawStrip1(tif, strip, (u_char *)tif->tif_rawdata,

		    bytecount, module) != bytecount)

			return (0);

		if (!isFillOrder(tif, td->td_fillorder) &&

		    (tif->tif_flags & TIFF_NOBITREV) == 0)

			TIFFReverseBits(tif->tif_rawdata, bytecount);

	}

	return (TIFFStartStrip(tif, strip));

}



/*

 * Tile-oriented Read Support

 * Contributed by Nancy Cam (Silicon Graphics).

 */



/*

 * Read and decompress a tile of data.  The

 * tile is selected by the (x,y,z,s) coordinates.

 */

tsize_t

TIFFReadTile(TIFF* tif,

    tdata_t buf, uint32 x, uint32 y, uint32 z, tsample_t s)

{

	if (!TIFFCheckRead(tif, 1) || !TIFFCheckTile(tif, x, y, z, s))

		return (-1);

	return (TIFFReadEncodedTile(tif,

	    TIFFComputeTile(tif, x, y, z, s), buf, (tsize_t) -1));

}



/*

 * Read a tile of data and decompress the specified

 * amount into the user-supplied buffer.

 */

tsize_t

TIFFReadEncodedTile(TIFF* tif, ttile_t tile, tdata_t buf, tsize_t size)

{

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t tilesize = tif->tif_tilesize;



	if (!TIFFCheckRead(tif, 1))

		return (-1);

	if (tile >= td->td_nstrips) {

		TIFFError(tif->tif_name, "%ld: Tile out of range, max %ld",

		    (long) tile, (u_long) td->td_nstrips);

		return (-1);

	}

	if (size == (tsize_t) -1)

		size = tilesize;

	else if (size > tilesize)

		size = tilesize;

	if (TIFFFillTile(tif, tile) && (*tif->tif_decodetile)(tif,

	    (tidata_t) buf, size, (tsample_t)(tile/td->td_stripsperimage))) {

		(*tif->tif_postdecode)(tif, (tidata_t) buf, size);

		return (size);

	} else

		return (-1);

}



static tsize_t

TIFFReadRawTile1(TIFF* tif,

    ttile_t tile, tdata_t buf, tsize_t size, const char* module)

{

	TIFFDirectory *td = &tif->tif_dir;



	if (!isMapped(tif)) {

		if (!SeekOK(tif, td->td_stripoffset[tile])) {

			TIFFError(module,

			    "%s: Seek error at row %ld, col %ld, tile %ld",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col,

			    (long) tile);

			return ((tsize_t) -1);

		}

		if (!ReadOK(tif, buf, size)) {

			TIFFError(module, "%s: Read error at row %ld, col %ld",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col);

			return ((tsize_t) -1);

		}

	} else {

		if (td->td_stripoffset[tile] + size > tif->tif_size) {

			TIFFError(module,

			    "%s: Seek error at row %ld, col %ld, tile %ld",

			    tif->tif_name,

			    (long) tif->tif_row,

			    (long) tif->tif_col,

			    (long) tile);

			return ((tsize_t) -1);

		}

		_TIFFmemcpy(buf, tif->tif_base + td->td_stripoffset[tile], size);

	}

	return (size);

}



/*

 * Read a tile of data from the file.

 */

tsize_t

TIFFReadRawTile(TIFF* tif, ttile_t tile, tdata_t buf, tsize_t size)

{

	static const char module[] = "TIFFReadRawTile";

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t bytecount;



	if (!TIFFCheckRead(tif, 1))

		return ((tsize_t) -1);

	if (tile >= td->td_nstrips) {

		TIFFError(tif->tif_name, "%lu: Tile out of range, max %lu",

		    (u_long) tile, (u_long) td->td_nstrips);

		return ((tsize_t) -1);

	}

	bytecount = td->td_stripbytecount[tile];

	if (size != (tsize_t) -1 && size < bytecount)

		bytecount = size;

	return (TIFFReadRawTile1(tif, tile, buf, bytecount, module));

}



/*

 * Read the specified tile and setup for decoding. 

 * The data buffer is expanded, as necessary, to

 * hold the tile's data.

 */

static int

TIFFFillTile(TIFF* tif, ttile_t tile)

{

	static const char module[] = "TIFFFillTile";

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t bytecount;



	bytecount = td->td_stripbytecount[tile];

	if (bytecount <= 0) {

		TIFFError(tif->tif_name,

		    "%lu: Invalid tile byte count, tile %lu",

		    (u_long) bytecount, (u_long) tile);

		return (0);

	}

	if (isMapped(tif) &&

	    (isFillOrder(tif, td->td_fillorder) || (tif->tif_flags & TIFF_NOBITREV))) {

		/*

		 * The image is mapped into memory and we either don't

		 * need to flip bits or the compression routine is going

		 * to handle this operation itself.  In this case, avoid

		 * copying the raw data and instead just reference the

		 * data from the memory mapped file image.  This assumes

		 * that the decompression routines do not modify the

		 * contents of the raw data buffer (if they try to,

		 * the application will get a fault since the file is

		 * mapped read-only).

		 */

		if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)

			_TIFFfree(tif->tif_rawdata);

		tif->tif_flags &= ~TIFF_MYBUFFER;

		if (td->td_stripoffset[tile] + bytecount > tif->tif_size) {

			tif->tif_curtile = NOTILE;

			return (0);

		}

		tif->tif_rawdatasize = bytecount;

		tif->tif_rawdata = tif->tif_base + td->td_stripoffset[tile];

	} else {

		/*

		 * Expand raw data buffer, if needed, to

		 * hold data tile coming from file

		 * (perhaps should set upper bound on

		 *  the size of a buffer we'll use?).

		 */

		if (bytecount > tif->tif_rawdatasize) {

			tif->tif_curtile = NOTILE;

			if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {

				TIFFError(module,

				"%s: Data buffer too small to hold tile %ld",

				    tif->tif_name, (long) tile);

				return (0);

			}

			if (!TIFFReadBufferSetup(tif, 0,

			    TIFFroundup(bytecount, 1024)))

				return (0);

		}

		if (TIFFReadRawTile1(tif, tile, (u_char *)tif->tif_rawdata,

		    bytecount, module) != bytecount)

			return (0);

		if (!isFillOrder(tif, td->td_fillorder) &&

		    (tif->tif_flags & TIFF_NOBITREV) == 0)

			TIFFReverseBits(tif->tif_rawdata, bytecount);

	}

	return (TIFFStartTile(tif, tile));

}



/*

 * Setup the raw data buffer in preparation for

 * reading a strip of raw data.  If the buffer

 * is specified as zero, then a buffer of appropriate

 * size is allocated by the library.  Otherwise,

 * the client must guarantee that the buffer is

 * large enough to hold any individual strip of

 * raw data.

 */

int

TIFFReadBufferSetup(TIFF* tif, tdata_t bp, tsize_t size)

{

	static const char module[] = "TIFFReadBufferSetup";



	if (tif->tif_rawdata) {

		if (tif->tif_flags & TIFF_MYBUFFER)

			_TIFFfree(tif->tif_rawdata);

		tif->tif_rawdata = NULL;

	}

	if (bp) {

		tif->tif_rawdatasize = size;

		tif->tif_rawdata = (tidata_t) bp;

		tif->tif_flags &= ~TIFF_MYBUFFER;

	} else {

		tif->tif_rawdatasize = TIFFroundup(size, 1024);

		tif->tif_rawdata = (tidata_t) _TIFFmalloc(tif->tif_rawdatasize);

		tif->tif_flags |= TIFF_MYBUFFER;

	}

	if (tif->tif_rawdata == NULL) {

		TIFFError(module,

		    "%s: No space for data buffer at scanline %ld",

		    tif->tif_name, (long) tif->tif_row);

		tif->tif_rawdatasize = 0;

		return (0);

	}

	return (1);

}



/*

 * Set state to appear as if a

 * strip has just been read in.

 */

static int

TIFFStartStrip(TIFF* tif, tstrip_t strip)

{

	TIFFDirectory *td = &tif->tif_dir;



	if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {

		if (!(*tif->tif_setupdecode)(tif))

			return (0);

		tif->tif_flags |= TIFF_CODERSETUP;

	}

	tif->tif_curstrip = strip;

	tif->tif_row = (strip % td->td_stripsperimage) * td->td_rowsperstrip;

	tif->tif_rawcp = tif->tif_rawdata;

	tif->tif_rawcc = td->td_stripbytecount[strip];

	return ((*tif->tif_predecode)(tif,

			(tsample_t)(strip / td->td_stripsperimage)));

}



/*

 * Set state to appear as if a

 * tile has just been read in.

 */

static int

TIFFStartTile(TIFF* tif, ttile_t tile)

{

	TIFFDirectory *td = &tif->tif_dir;



	if ((tif->tif_flags & TIFF_CODERSETUP) == 0) {

		if (!(*tif->tif_setupdecode)(tif))

			return (0);

		tif->tif_flags |= TIFF_CODERSETUP;

	}

	tif->tif_curtile = tile;

	tif->tif_row =

	    (tile % TIFFhowmany(td->td_imagewidth, td->td_tilewidth)) *

		td->td_tilelength;

	tif->tif_col =

	    (tile % TIFFhowmany(td->td_imagelength, td->td_tilelength)) *

		td->td_tilewidth;

	tif->tif_rawcp = tif->tif_rawdata;

	tif->tif_rawcc = td->td_stripbytecount[tile];

	return ((*tif->tif_predecode)(tif,

			(tsample_t)(tile/td->td_stripsperimage)));

}



static int

TIFFCheckRead(TIFF* tif, int tiles)

{

	if (tif->tif_mode == O_WRONLY) {

		TIFFError(tif->tif_name, "File not open for reading");

		return (0);

	}

	if (tiles ^ isTiled(tif)) {

		TIFFError(tif->tif_name, tiles ?

		    "Can not read tiles from a stripped image" :

		    "Can not read scanlines from a tiled image");

		return (0);

	}

	return (1);

}



void

_TIFFNoPostDecode(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif; (void) buf; (void) cc;

}



void

_TIFFSwab16BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 1) == 0);

    TIFFSwabArrayOfShort((uint16*) buf, cc/2);

}



void

_TIFFSwab32BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 3) == 0);

    TIFFSwabArrayOfLong((uint32*) buf, cc/4);

}



void

_TIFFSwab64BitData(TIFF* tif, tidata_t buf, tsize_t cc)

{

    (void) tif;

    assert((cc & 7) == 0);

    TIFFSwabArrayOfDouble((double*) buf, cc/8);

}

